[FIX] packaging: adapt Odoo version in windows installer

Packaging oversight, the displayed version in the installer window was still
12.0.

closes odoo/odoo#38486

X-original-commit: c5bd1a4f
Signed-off-by: Christophe Monniez (moc) <moc@odoo.com>

setup/win32/setup.nsi

@@ -41,7 +41,7 @@
 !define PUBLISHER 'Odoo S.A.'
 
 !ifndef MAJOR_VERSION
-    !define MAJOR_VERSION '12'
+    !define MAJOR_VERSION '13'
 !endif
 
 !ifndef MINOR_VERSION